This proposed discusses the identification, evaluation and development of novel breast cancer markers for the diagnosis and prognosis of human breast.cancer. Breast cancer is second only to long cancer in deaths among women in the U.S. Good prognosis depends ont he early detection of the disease. However, the sensitivity and the specificity of the current available diagnostic markers is not sufficient. Using improved state of the art technology, differential display PCR and the sensitive, specific RT-PCR characterization procedures, we have identified 4 novel breast cancer markers. These novel genes will be further evaluated alone and/or in combination to determine the optimal combination of genes for use in RT-PCR assays and provide the most utility in diagnosis and/or prognosis of breast cancer. Advances have already been achieved at Corixa in identifying these novel cancer markers. This in combination with collaborations with key investigators in he area of breast and prostate cancer and access to an extensive blood and tissue bank should enable the goals and objectives of this proposal to be achieved. PROPOSED COMMERCIAL APPLICATION: The proposed studies will led to commercialization of an RT-PCR assay for diagnosis and?or prognosis of breast cancer. Such tests would be marketed both in the U.S. and worldwide. The estimated world wide market for such a tests is $200-300 million/year.